Connect Door Arm To Trolley - Chamberlain 3280CM 1/2 HP Owner's Manual

INSTALLATION STEP 12

Connect Door Arm to Trolley

Follow instructions which apply to your door type as
illustrated below and on the following page.
SECTIONAL DOORS ONLY
• Make sure garage door is fully closed. Pull the
emergency release handle to disconnect the outer trolley
from the inner trolley. Slide the outer trolley back (away
from the door) about 2" (5 cm) as shown in Figures 1, 2
and 3.
• Figure 1:
– Fasten straight door arm section to outer trolley with
the 5/16"x1" clevis pin. Secure the connection with a
ring fastener.
– Fasten curved section to the door bracket in the same
way, using the 5/16"x1-1/4" clevis pin.
• Figure 2:
– Bring arm sections together. Find two pairs of holes
that line up and join sections. Select holes as far apart
as possible to increase door arm rigidity.
• Figure 3, Hole alignment alternative:
– If holes in curved arm are above holes in straight arm,
disconnect straight arm. Cut about 6" (15 cm) from the
solid end. Reconnect to trolley with cut end down
as shown.
– Bring arm sections together.
– Find two pairs of holes that line up and join with bolts,
lock washers and nuts.
• Pull the emergency release handle toward the opener at
a 45° angle so that the trolley release arm is horizontal.
Proceed to Adjustment Step 1, page 23. Trolley will
re-engage automatically when opener is operated.
HARDWARE SHOWN ACTUAL SIZE
Nut 5/16"-18 Lock Washer 5/16"
Clevis Pin
5/16"x1" (Trolley)
Ring Fastener
Hex Bolt
Clevis Pin
5/16"x1-1/4" (Door Bracket) 5/16"-18x7/8"
Outer Trolley
Ring
Fastener
Door
Bracket
Clevis Pin
5/16"x1-1/4"
Figure 1
Nuts
5/16"-18
Door Bracket
Figure 2
Nuts
5/16"-18
Figure 3
21
Inner Trolley
Clevis Pin
5/16"x1"
Straight
Door Arm
Curved
Door Arm
Lock
Washers
5/16"
Emergency
Release
Handle
Bolts
5/16"-18x7/8"
Lock
Washers
5/16"
Bolts
5/16"-18x7/8"
Cut This End